system hang with backports-20150511/20150525

[Marty Faltesek]

I disabled IEEE80211_HW_SUPPORT_FAST_XMIT before, and still saw the
hang. I repeated today to confirm.

I added the extra ath10k debug flags you requested, and it causes a
system reset without any messages, very soon after the last hbeat
timestamp. I've uploaded  log "crash.6.1.15.13.46" to
http://tinyurl.com/dmesg-ftrace.

Any advice on how to bisect when using backports?

On Mon, Jun 1, 2015 at 4:27 AM, Michal Kazior <michal.kazior at tieto.com> wrote:
> On 1 June 2015 at 09:13, Kalle Valo <kvalo at qca.qualcomm.com> wrote:
>> Michal Kazior <michal.kazior at tieto.com> writes:
>>
>>> +ath10k list
>>>
>>> On 1 June 2015 at 03:37, Marty Faltesek <mfaltesek at google.com> wrote:
>>>> Starting with backports-20150511, and continuing with
>>>> backports-20150525, we see frequent system hangs. backports-20150424
>>>> had no issue.
>>>
>>> I don't see such binary releases on
>>> https://backports.wiki.kernel.org/index.php/Main_Page
>>> Hence I don't know what kernel you've backported the drivers from and
>>> I can't compare anything.
>>>
>>> Can you provide more details, please?
>>
>> I suspect it's from here:
>>
>> https://www.kernel.org/pub/linux/kernel/projects/backports/2015/05/25/
>>
>> The backports project pages are a bit confusing and that location is
>> hard to find.
>
> Oh, thanks!
>
> Hmm.. There was a ton of changes between 20150424 and 20150511. For
> one, ath10k started to use chanctx API and FAST_XMIT. But it's not a
> given these two are to blame.
>
> The latter can be easily disabled by removing
> IEEE80211_HW_SUPPORT_FAST_XMIT from ar->hw->flags in ath10k's mac.c.
> The former.. not so easy. I'd be awesome if you could do a git bisect.
> The commit ids are a3da0fb6(good) f17107c(bad) (you need linux-next
> git repo including its tags for these ids to be resolvable).
>
>
> Michał